Dampers placed on the half face of the inlet and the outlet of side-by-side airflow energy recovery sections used as recirculation path

ABSTRACT

An air handler includes a housing with a heat exchanger core. The housing includes a faceplate, a roof panel, a base panel, a first side panel, and a second side panel. A first tunnel and a second tunnel are connected to the housing at the faceplate. A septum protrudes from the faceplate and connects the core at a front edge. The air handler further includes a first recirculation path and a second recirculation path inside the housing. The first and second recirculation paths are defined by the septum, the housing, and the core. The first and second recirculation paths are configured to direct a portion of airflow from the first tunnel to the second tunnel. The air handler further includes a first damper and a second damper disposed on the faceplate and configured to obstruct the first recirculation path and the second recirculation path respectively.

FIELD

This disclosure relates generally to an air handler with recirculationdampers for a heating, venting, air conditioning, and refrigeration(HVACR) system, particularly the arrangement, construction, and/orconfiguration of the recirculation dampers in the air handler.

BACKGROUND

A heat exchange assembly, such as an air handler with a heat exchangercore, can help mechanical ventilation of a controlled space be morecost-effective by reclaiming a portion of energy from vented indoor airbefore exhausting the vented indoor air into the environment. The ventedindoor air and the fresh air exchange energy in the core and recapture aportion of the energy from the vented indoor air that would otherwise belost if the vented indoor air were exhausted directly to theenvironment. The air handler can further reduce energy consumption byrecirculating the vented indoor air into the controlled space whilebypassing the core. The recirculation function can be achieved byrecirculation dampers installed for the air handler.

SUMMARY

This disclosure relates generally to an air handler with recirculationdampers for a heating, venting, air conditioning, and refrigeration(HVACR) system, particularly the arrangement, construction, and/orconfiguration of recirculation dampers in the air handler.

By including dampers on a faceplate of an air handler housing instead ofon a middle of unit wall shared by an indoor air inlet tunnel and anindoor air return tunnel connected to the air handler, flow ofrecirculation path within the air handler can be improved while savingspace. By placing the dampers on the face of the air handler housinginstead of the middle of unit wall, the tunnels connected to the airhandler do not need to account for the size requirements of the damper.Accordingly, more compact recirculation flow paths can be used whilestill achieving sufficient flow and good pressure drop properties acrossthe air handler.

According to an embodiment, an air handler for an HVACR system includesa housing. The housing includes a faceplate, a roof panel, a base panel,a first side panel, and a second side panel. A septum protrudes into thehousing from a first side of the faceplate. A core is disposed withinthe housing and has a front edge connected to an edge of the septum, atop edge connected to the roof panel, a bottom edge connected to thebase panel, a first side plate connected to the first side panel, and asecond side plate connected to the second side panel. A first tunnelconnects to a first area on the faceplate from a second side of thefaceplate. The second side is opposite to the first side of thefaceplate. A second tunnel connects to a second area of the faceplatefrom the second side. The second area is disjointed from the first area.A first recirculation path is defined by the faceplate, the roof panel,the septum, the first side panel, the second side panel, and the core.The first recirculation path is configured to channel a first portion ofairflow from the first tunnel to the second tunnel. A secondrecirculation path is defined by the faceplate, the septum, the basepanel, the first side panel, the second side panel, and the core. Thesecond recirculation path is configured to channel a second portion ofthe airflow from the first tunnel to the second tunnel. A first damperis disposed in the first area of the faceplate and configured toobstruct the first recirculation path. A second damper is disposed inthe second area of the faceplate and configured to obstruct the secondrecirculation path. A first opening is disposed in the first area of thefaceplate and connecting the first tunnel to the second recirculationpath. A second opening is disposed in the second area of the faceplateand connecting the second tunnel to the first recirculation path.

According to another embodiment, the second damper is disposed adjacentto the first side panel and the roof panel, and the first damper isdisposed adjacent to the second side panel and the base panel.

According to yet another embodiment, the second opening is adjacent tothe first side panel and the base panel, and the first opening isadjacent to the second side panel and the roof panel.

According to yet another embodiment, the first tunnel is an indoor airinlet from a controlled space, and the second tunnel is an indoor airreturn to the controlled space.

According to yet another embodiment, the core is a fixed plate heatexchanger or a rotary type wheel heat exchanger.

According to yet another embodiment, the core is in a horizontalconfiguration substantially parallel to the septum, and the fixed plateheat exchanger includes heat transfer plates that are in a verticalconfiguration when the core includes a fixed plate heat exchanger, andthe rotary type wheel heat exchanger includes at least two side-by-sidewheels when the core includes a rotary type wheel heat exchanger.

According to yet another embodiment, the first tunnel and the secondtunnel are separated by a middle of unit wall that is substantiallyperpendicular to the faceplate on a first plane and substantiallyperpendicular to the septum on a second plane, wherein the second planeis substantially perpendicular to the first plane.

According to yet another embodiment, the first damper includes aplurality of sections that are configured to open or close independentlyamong one another or in unison, and the second damper includes aplurality of sections that are configured to open or close independentlyamong one another or in unison.

According to yet another embodiment, the first damper obstructs thefirst portion of the airflow from entering the first recirculation pathwhen the first damper is in a closed position.

According to yet another embodiment, the second damper obstructs thesecond portion of the airflow from entering the second tunnel when thesecond damper is in a closed position.

According to yet another embodiment, the first portion of the airflow isrecirculated to the second tunnel through the second opening when thefirst damper is in an open position, and the second portion of theairflow is recirculated to the second tunnel through the first openingand the second recirculation path when the second damper is in an openposition.

According to yet another embodiment, the airflow entered the firsttunnel from a controlled space is recirculated into the controlled spacewhen the first and the second dampers are in their open positions.

According to yet another embodiment, the core further includes at leastone of a bypass damper or a defrost damper.

According to one embodiment, a method of providing recirculationcapabilities using an air handler with a core, includes opening a firstdamper and a second damper; receiving vented indoor air from acontrolled space through a first tunnel; channeling a first portion ofthe vented indoor air from the first tunnel to a second tunnel throughthe first damper, a first recirculation path, and a second opening;channeling a second portion of the vented indoor air from the firsttunnel to the second tunnel through a first opening, a secondrecirculation path, and the second damper; and returning the firstportion of the vented indoor air and the second portion of the ventedindoor air from the second tunnel into the controlled space. The airhandler has a housing that includes a faceplate, a roof panel, a basepanel, a first side panel, and a second side panel. The firstrecirculation path and the second recirculation path are separated by aseptum protruding into the housing from a first side of the faceplate.The housing contains the core having a top edge connected to the roofpanel, a bottom edge connected to the base panel, a front edge connectedto the septum, a first side plate connected to the first side panel, anda second side plate connected to the second side panel. The first tunnelconnects to the faceplate at a first area of a second side of thefaceplate. The second side is opposite to the first side of thefaceplate. The second tunnel connects to the faceplate at a second areaof the first side of the faceplate. The second area is disjointed fromthe first area. The first damper and the first opening are disposed inthe first area on the faceplate. The second damper and the secondopening are disposed in the second area on the faceplate. The firstrecirculation path is defined by the roof panel, the faceplate, thefirst side panel, the second side panel, the septum, and the core. Thesecond recirculation path is defined by the base panel, the faceplate,the first side panel, the second side panel, the septum, and the core.

According to another embodiment, the method further includes closing thefirst damper and the second damper; obstructing the vented indoor air inthe first tunnel from entering into the first recirculation path;channeling the vented indoor air in the first tunnel into the secondrecirculation path through the first opening; channeling the ventedindoor air in the second recirculation path into the core; channelingfresh air into the core; exchanging energy in the core between thevented indoor and the fresh air; channeling the fresh air in the coreinto the first recirculation path; obstructing the fresh air in thefirst recirculation path from entering into the first tunnel; channelingthe fresh air in the first recirculation path into the second tunnelthrough the second opening; exhausting the vented indoor air from thecore after exchanging energy; and channeling the fresh air from thesecond tunnel to the controlled space.

According to yet another embodiment, the second damper is disposedadjacent to the first side panel and the roof panel, and the firstdamper is disposed adjacent to the second side panel and the base panel,and the second opening is adjacent to the second side panel and the roofpanel, and the first opening is adjacent to the first side panel and thebase panel.

According to yet another embodiment, the first tunnel is an indoor airinlet from the controlled space, and the second tunnel is an indoor airreturn to the controlled space.

According to yet another embodiment, the core is a fixed plate heatexchanger or a rotary type wheel heat exchanger.

According to yet another embodiment, the core is in a horizontalconfiguration substantially parallel to the septum, and the fixed plateheat exchanger includes heat transfer plates that are in a verticalconfiguration when the core includes a fixed plate heat exchanger, andthe rotary type wheel heat exchanger includes at least two side-by-sidewheels.

According to yet another embodiment, the first tunnel and the secondtunnel are separated by a middle of unit wall that is substantiallyperpendicular to the faceplate on a first plane and substantiallyperpendicular to the septum on a second plane, wherein the second planeis substantially perpendicular to the first plane.

According to yet another embodiment, the first damper includes aplurality of sections that are configured to open or close independentlyamong one another or in unison, and the second damper includes aplurality of sections that are configured to open or close independentlyamong one another or in unison.

According to yet another embodiment, the core is a counter flow air toair heat exchanger.

According to yet another embodiment, the core is a rotary type wheelheat exchanger. For example, the core can be at least two side-by-sideenergy wheels (“EW”), cool-dry-quiet (“CDQ”) desiccant wheels, ordehumidification wheels.

BRIEF DESCRIPTION OF THE DRAWINGS

References are made to the accompanying drawings that form a part ofthis disclosure, and which illustrate embodiments in which the systemsand methods described herein can be practiced.

FIG. 1A is a perspective view of an air handler with recirculationcapabilities according to one embodiment.

FIG. 1B is a side view of the air handler in a ventilating modeaccording to the embodiment of FIG. 1A.

FIG. 1C is a perspective view of the air handler in a recirculation modeaccording to the embodiment of FIG. 1A.

FIG. 1D is a top view of the air handler in a recirculation modeaccording to the embodiment of FIG. 1A.

FIG. 2A is a perspective view of an air handler with recirculationcapabilities according to another embodiment.

FIG. 2B is a side view of the air handler in a ventilating modeaccording to the embodiment of FIG. 2A.

FIG. 2C is a perspective view of the air handler in a recirculation modeaccording to the embodiment of FIG. 2A.

FIG. 2D is a top view of the air handler in a recirculation modeaccording to the embodiment of FIG. 2A.

FIG. 3A is a side view of the air handler according to the embodiment ofFIG. 1A, to illustrate space savings.

FIG. 3B is a side view of a known air handler to illustrate spacesavings of the air handler of FIG. 1A.

FIG. 4A a side view of the air handler according to the embodiment ofFIG. 2A, to illustrate space savings.

FIG. 4B is a side view of a known air handler to illustrate spacesavings compared to the air handler of FIG. 2A.

Like reference numbers represent like parts throughout.

DETAILED DESCRIPTION

This disclosure relates generally to an air handler with recirculationdampers for a heating, venting, air conditioning, and refrigeration(HVACR) system, particularly the arrangement, construction, and/orconfiguration of the recirculation dampers in the air handler.

FIG. 1A is a perspective view of an air handler 100 with recirculationcapabilities, according to one embodiment. As shown in FIG. 1A, airhandler 100 includes a housing and a heat exchanger core 125.

The housing includes the faceplate 114, a rear faceplate 114A, a roofpanel 162 (shown in FIG. 1B), a base panel 164 (shown in FIG. 1B), afirst side panel 166 (shown in FIG. 1D), and a second side panel 168(shown in FIG. 1D). According to an embodiment, the he air handler 100further includes a septum 170, or alternatively referred to as a septumpanel 170, protruding from a first side of the faceplate 114. The septum170 extends from the first side panel 166 on one end of the septum 170,to the second side panel 168 on the other end of the septum 170. Theseptum 170 is joined to the faceplate 114 on one side of the septum 170,and to the core 125 on the other side of the septum 170.

The heat exchanger core 125 can alternatively be referred to as the core125 or an energy recovery section 125. The housing connects to a firsttunnel 130 and a second tunnel 140 at a faceplate 114 of the air handler100.

FIG. 1B is a side view of the air handler 100 in a ventilating mode,according to the embodiment of FIG. 1A. As shown in FIG. 1B, the airhandler 100 further includes at least one of a top block-off 170A, abottom block-off 170B, or a rear septum 170C, according to anembodiment. The core 125 is disposed inside the housing. The core 125includes a top edge 126, a bottom edge 128, a front edge 127, and a backedge 129. The top block-off 170A connects the top edge 126 to the roofpanel 162. The bottom block-off 170B connects a bottom edge 128 to thebase panel 164. The septum 170 connects the front edge 127 to thefaceplate 114. The rear septum 170C connects the back edge 129 to therear faceplate 114A.

FIG. 1C is a perspective view of the air handler 100 in a recirculationmode, according to the embodiment of FIG. 1A. As shown in FIG. 1C, thefirst tunnel 130 connects to a second side of the faceplate 114 at afirst area. The second side of the faceplate 114 is opposite to thefirst side of the faceplate 114 where the septum 170 protrudes from. Thefirst tunnel 130 introduces vented indoor air into the housing. Thevented indoor air can be indoor air removed from a controlled space andbefore the indoor air is exhausted to the outside environment. Thecontrolled space is served by an HVACR system, and the controlled spacecan be a room, an office, a building, or the like. According to anembodiment, the vented indoor air from the controlled space is heated orcooled to a desired temperature that is generally different from thetemperature of untreated fresh air from the outside environment. Withouta core in the air handler, the vented indoor is exhausted into theenvironment, and nearly all the energy consumed to heat or cool thevented air would have been lost.

The second tunnel 140 connects to the faceplate 114 on the second sideof the faceplate 114. The second side of the faceplate 114 is the sameside of the faceplate 114 where the first tunnel 130 also connects tothe faceplate 114. The second tunnel 140 connects to the second side ata second area that is disjointed from the first area connected to thefirst tunnel 130. According to an embodiment, the first area and thesecond area are adjacent to but separated from each other at where amiddle of unit wall 150 connects to the faceplate 114

A first damper 116 is disposed on the faceplate 114 within the firstarea. The first damper 116 connects a portion of the first tunnel 130 toa first recirculation path 110A. A first opening 118 is disposed on thefaceplate 114 within the first area. The first opening 118 connectsanother portion of the first tunnel 130 to a second recirculation path110B. A second damper 120 is disposed on faceplate 114 within the secondarea. The second damper 120 connects a portion of the second tunnel 140to the second recirculation path 110B. A second opening 122 is disposedon the faceplate 114 within the second area. The second opening 122connects another portion of the second tunnel 140 to the firstrecirculation path 110A.

According to one embodiment, the first damper 116 is disposed on a lowerportion of the faceplate 114 below the septum 170. The second opening122 is disposed on the lower portion of the faceplate 114 below theseptum 170. The second damper 120 is disposed on an upper portion of thefaceplate 114 below the septum 170. The first opening 118 is disposed onthe upper portion of the faceplate 114 below the septum 170.

According to another embodiment, the first damper 116 occupiesapproximately one half of the first area on the faceplate 114. The firstopening 118 occupies approximately the other half of the first area. Thesecond damper 120 occupies approximately one half of the second area onthe faceplate 114. The second opening 122 occupied approximately theother half of the second area. Further, the first damper 116, the firstopening 118, the second damper 120, and the second opening 122 eachoccupies a portion of the faceplate 114 that are disjointed from oneanother.

The first tunnel 130 conducts the vented indoor air into the air handler100 via the first damper 116 and the first opening 118. Accordingly, thefirst tunnel 130 functions as an indoor air intake 132. The secondtunnel 140 conducts air from the air handler 100 to the controlled spacevia the second damper 120 and the second opening 122. Accordingly, thesecond tunnel 140 functions as an indoor air return 142. The firsttunnel 130 and the second tunnel 140 are separated by a middle of unitwall 150. In an embodiment, the middle of unit walls 150 issubstantially perpendicular to the faceplate 114 on a first plane andsubstantially perpendicular to the septum 170 on a second plane.Further, the second plane is substantially perpendicular to the firstplane.

FIG. 1D is a top view of the air handler 100 in a recirculation mode,according to the embodiment of FIG. 1A. As shown in FIGS. 1B and 1D, thecore 125 within the air handler 100 has a top edge 126, a front edge127, a bottom edge 128, and a back edge 129. The core 125 connects tothe septum 170 at the front edge 127. A top surface 125A of the core 125is located between the top edge 126 and the front edge 127, and a bottomsurface 125B of the core 125 is located between the bottom edge 128 andthe front edge 127. The core 125 further includes a first side plate125C connected to the first side panel 166 of the air handler 100 and asecond side plate 125D connected to the second side panel 168 of airhandler 100. According to one embodiment, the core 125 is disposed in ahorizontal configuration with heat exchanger plates (not shown) of thecore 125 in a vertical configuration. According to one embodiment, thecore 125 is in a horizontal configuration when the top edge 126, thefront edge 127, the bottom edge 128, or the back edge 129 isperpendicular to the middle of unit wall 150 that separates the firsttunnel 130 and the second tunnel 140.

The second recirculation path 110B of the air handler 100 is defined bythe roof panel 162, the faceplate 114, the septum 170, the first sidepanel 166, the second side panel 168, and the core 125. The firstrecirculation path 110A of the air handler 100 is defined by the basepanel 165, the faceplate 114, the septum 170, the first side panel 166,the second side panel 168, and the core 125. The first recirculationpath 110A and the second recirculation path 110B are inside the housingand are separated by the septum 170.

According to one embodiment, the second recirculation path 110B of theair handler 100 is defined by the roof panel 162, the faceplate 114, theseptum 170, the first side panel 166, the second side panel 168, and thetop surface 125A. The first recirculation path 110A of the air handler100 is defined by the base panel 164, the faceplate 114, the septum 170,the first side panel 166, the second side panel 168, and the bottomsurface 125B.

As shown in FIGS. 1B and 1C, the air handler can 100 be in a circulationmode or a ventilation mode. In the ventilation mode, the first damper116 is in a closed position, the first damper 116 obstructs the ventedindoor air from the indoor air intake 132 entering the firstrecirculation path 110A and further obstructs the vented indoor air fromentering the second tunnel 140 downstream from the first damper 116.When the second damper 120 is in a closed position, vented indoor airfrom the indoor air intake 132 is allowed into to pass through the firstopening 118, but the second damper 120 obstructs the vented indoor airin the second recirculation path 110B from entering the second tunnel140. Accordingly, the indoor air from the indoor air intake 142 isobstructed from recirculating into the controlled space through thesecond tunnel 140 as the indoor air return 142. Accordingly, when thefirst and the second dampers 116 and 120 are both in their closedpositions, vented indoor air entered into the first tunnel 130 isprimarily exhausted after exchanging heat in the core 125.

In the recirculation mode, the first damper 116 is in an open position,a first portion of the vented indoor air from the indoor air intake 132can flow through the first damper 116 into the first recirculation path110A. The first portion of the vented indoor air in the firstrecirculation path 110A can further enter into the second tunnel 140through the second opening 122 as a portion of the indoor air return142. Accordingly, when the first damper 116 is in the open position, thefirst portion of the vented indoor air from the indoor air intake 132 isrecirculated through the first recirculation path 110A into the secondtunnel 140 as a portion of the indoor air return 142. The vented indoorair from the indoor air intake 132 is recirculated back to thecontrolled space.

In the recirculation mode, the second damper 120 is in an open position.A second portion of the vented indoor air from the indoor air intake 132can flow through the first opening 118 into the second recirculationpath 110B. The second portion of the vented indoor air in the secondrecirculation path 110B can further flow through the opened seconddamper 120 into the second tunnel 140 as another portion of the indoorair return 142. Accordingly, when the second damper 120 is in the openposition, the second portion of the vented indoor air from the indoorair intake 132 is recirculated through the second recirculation path110B into the second tunnel 140 as another portion of the indoor airreturn 142. The indoor air from the indoor air intake 132 isrecirculated back to the controlled space. Further, when the firstdamper 116 and the second damper 120 are both in their open positions, aportion of the indoor air from the first tunnel 130 is recirculatedthrough the second tunnel 140 and back into the controlled space.

It is appreciated that, although the first damper 116 and the seconddamper 120 are depicted to have horizontal blades with linkages operatedwith rotary actuators, the dampers 116 and 120 are no limited to hisconfiguration. According to one embodiment, the dampers 116 and 120 canbe vertical blade type dampers. The blades on each of the recirculationdampers parallel blade configuration or an opposed blade configuration,or a combination of both. According to another embodiment, the dampers116 and 120 can be any type of damper that obstruct airflow. It is alsoappreciated that, when the first damper 116 includes a plurality ofsections, each of the sections can be operated independently from oneanother or in unison. When the second damper 120 includes a plurality ofsections, each of the sections can be operated independently from oneanother or in unison. It is appreciated that the first damper 116 andthe second damper 120 can be operated independently or in unison.

In the ventilation mode, energy is recovered in the core 125. The firstdamper 116 is in the closed position and obstructs the vented indoor airin the first tunnel 130 from entering into the first recirculation path110A. The vented indoor air flows into the second recirculation path110B through the first opening 118. The second damper 118 is in theclosed position and obstructs the vented indoor in the secondrecirculation oath 110B from entering the second tunnel 140.Accordingly, the vented indoor air enters into the core 125. Fresh airfrom the environment enters the core 125 through the rear faceplate 114Aand exchanges energy with the vented indoor air in the core 125. Afterpassing the core 125, the fresh air enters into the first recirculationpath 110A. The fresh air is obstructed by the first damper 116 andchanneled into the second tunnel 140 through the second opening 122. Thefresh air in the second tunnel 140 becomes the indoor air return 142 andis further channeled into the controlled space. The vented indoor air isexhausted into the environment after passing the core 125.

FIG. 2A is a perspective view of an air handler 200 with recirculationcapabilities, according to another embodiment. As shown in FIG. 2A, airhandler 200 includes a housing and a heat exchanger core 225.

The housing includes the faceplate 114, a rear faceplate 114A, a roofpanel 162 (shown in FIG. 2B), a base panel 164 (shown in FIG. 2B), afirst side panel 166 (shown in FIG. 2D), and a second side panel 168(shown in FIG. 2D). According to an embodiment, the air handler 200further includes a septum 270, or a septum panel 270, protruding from afirst side of the faceplate 114. The septum 270 connects to the firstside panel 166 on one end of the septum 270, to the second side panel168 on the other end of the septum 270, to the faceplate 114 on one sideof the septum 270, and to the core 225 on the other side of the septum270.

The heat exchanger core 225 can be alternatively referred to as the core225 or an energy recovery section 225. The housing connects to a firsttunnel 130 and a second tunnel 140 at a faceplate 114 of the air handler200.

FIG. 2B is a side view of the air handler 200 in a ventilating mode,according to the embodiment of FIG. 2A. As shown in FIG. 2B, the airhandler 200 further includes at least one of a top block-off 270A, abottom block-off 270B, or a rear septum 270C, according to anembodiment. The core 225 is disposed inside the housing. The core 225includes a top edge 226 or a top surface 226, a bottom edge 228 or abottom surface 228, a front edge 227 or a front surface 227, and a backedge 229 or a back surface 229. The top block-off 270A connects the topedge 226 to the roof panel 162. The bottom block-off 270B connects abottom edge 228 to the base panel 164. The septum 270 connects the frontedge 227 to the faceplate 114. The rear septum 270C connects the backedge 229 to the rear faceplate 114A.

FIG. 2C is a perspective view of the air handler 200 in a recirculationmode, according to the embodiment of FIG. 2A. As shown in FIG. 2C, thefirst tunnel 230 connects to a second side of the faceplate 114 at afirst area. The second side of the faceplate 114 is opposite to thefirst side of the faceplate 114 where the septum 270 protrudes from.According to one embodiment, the first tunnel 130 introduces ventedindoor air into the housing. The vented indoor air is indoor air removedfrom a controlled space and before the indoor air is exhausted to theoutside environment. The controlled space is served by an HVACR system,and the controlled space can be a room, an office, a building, or thelikes. According to an embodiment, the vented indoor air from thecontrolled space is heated or cooled to a desired temperature that isgenerally different from the temperature of untreated fresh air from theoutside environment. Without a core in the air handler, the ventedindoor is exhausted into the environment, and nearly all the energyconsumed to heat or cool the vented air would have been lost.

The second tunnel 140 connects to the faceplate 114 on the second sideof the faceplate 114. The second side of the faceplate 114 is the sameside of the faceplate 114 where the first tunnel 130 also connects tothe faceplate 114. The second tunnel 140 connects to the second side ata second area that is disjointed from the first area connected to thefirst tunnel 130. According to an embodiment, the first area and thesecond area are adjacent to and disjointed from each other at where amiddle of unit wall 150 connects to the faceplate 114.

A first damper 116 is disposed on the faceplate 114 within the firstarea. The first damper 116 connects a portion of the first tunnel 130 toa first recirculation path 210A. A first opening 118 is disposed on thefaceplate 114 within the first area. The first opening 118 connectsanother portion of the first tunnel 130 to a second recirculation path210B. A second damper 120 is disposed on faceplate 114 within the secondarea. The second damper 120 connects a portion of the second tunnel 140to the second recirculation path 210B. A second opening 122 is disposedon the faceplate 114 within the second area. The second opening 122connects another portion of the second tunnel 140 to the firstrecirculation path 210A.

According to one embodiment, the first damper 116 is disposed on a lowerportion of the faceplate 114 below the septum 270. The second opening122 is disposed on the lower portion of the faceplate 114 below theseptum 270. The second damper 120 is disposed on an upper portion of thefaceplate 114 above the septum 270. The first opening 118 is disposed onthe upper portion of the faceplate 114 above the septum 270.

According to another embodiment, the first damper 116 occupiesapproximately one half of the first area on the faceplate 114. The firstopening 118 occupies approximately the other half of the first area. Thesecond damper 120 occupies approximately one half of the second area onthe faceplate 114. The second opening 122 occupied approximately theother half of the second area. Further, the first damper 116, the firstopening 118, the second damper 120, and the second opening 122 eachoccupies a portion of the faceplate 114 that are disjointed from oneanother.

The first tunnel 130 conducts the vented indoor air into the air handler200 via the first damper 116 and the first opening 118. Accordingly, thefirst tunnel 130 functions as an indoor air intake 132. The secondtunnel 140 conducts air from the air handler 100 to the controlled spacevia the second damper 120 and the second opening 122. Accordingly, thesecond tunnel 140 functions as an indoor air return 142. The firsttunnel 130 and the second tunnel 140 are separated by the middle of unitwall 150. According to an embodiment, the middle of unit wall 150 issubstantially perpendicular to the faceplate 114 on a first plane andsubstantially perpendicular to the septum 270 on a second plane.Further, the second plane is substantially perpendicular to the firstplane.

FIG. 1D is a top view of the air handler 200 in a recirculation mode,according to the embodiment of FIG. 2A. As shown in FIGS. 2B and 2D, thecore 225 within the air handler 200 has a top edge 226, a front edge227, a bottom edge 228, and a back edge 229. The core 225 connects tothe septum 270 at the front edge 227. A top surface 225A of the core 225is located between the top edge 226 and the front edge 227, and a bottomsurface 225B of the core 225 is located between the bottom edge 228 andthe front edge 227. The core 225 further includes a first side plate225C connected to the first side panel 166 of the air handler 200 and asecond side plate 225D connected to the second side panel 168 of the airhandler 200. According to one embodiment, the core 225 is disposed in aside-by-side dual wheel configuration with heat exchanger wheels of thecore 225 configured to rotate in the same vertical plane substantiallyparallel to the faceplate 114, and the centers of rotation of both heatexchanger wheels are in a line substantially overlaps the intersectionof the vertical plane of the rotating dual-wheels and the septum 270.According to one embodiment, the core 225 includes at least threeside-by-side heat exchanger wheels.

The second recirculation path 210B (shown in FIG. 2C) of the air handler200 is defined by the roof panel 162, the faceplate 114, the septum 270,the first side panel 166, the second side panel 168, and the core 225.The first recirculation path 210A (shown in FIG. 2C) of the air handler200 is defined by the base panel 165, the faceplate 114, the septum 270,the first side panel 166, the second side panel 168, and the core 225.The first recirculation path 210A and the second recirculation path 210Bare inside the housing and are separated by the septum 270.

According to one embodiment, the second recirculation path 210B of theair handler 200 is defined by the roof panel 162, the faceplate 114, theseptum 270, the first side panel 166, the second side panel 168, and thetop surface 225A. The first recirculation path 210A of the air handler100 is defined by the base panel 164, the faceplate 114, the septum 170,the first side panel 166, the second side panel 168, and the bottomsurface 225B. According to another embodiment where at least one of thefirst side plate 225C, the second side plate 225D, the top block-off170A, or the bottom block-off 170A is included in the air handler 200.The second recirculation path 210B is further defined the at least oneof the first side plate 225C, the second side plate 225D, the topblock-off 170A included in the air handler 200. The first recirculationpath 210A is further defined the at least one of the first side plate225C, the second side plate 225D, the bottom block-off 170B included inthe air handler 200.

As shown in FIGS. 2B and 2C, the air handler 200 can be in a circulationmode or a ventilation mode. In the ventilation mode, the first damper116 is in a closed position, the first damper 116 obstructs the ventedindoor air from the indoor air intake 132 entering the firstrecirculation path 210A and further obstructs the vented indoor air fromentering the second tunnel 140 downstream from the first damper 116 viathe first recirculation path 210A. When the second damper 120 is in aclosed position, vented indoor air from the indoor air intake 132 isallowed into the second recirculation path 210B through the firstopening 118, but the second damper 120 obstructs the vented indoor airin the second recirculation path 210B from entering the second tunnel140. Accordingly, the indoor air from the indoor air intake 142 isobstructed from recirculating into the controlled space through thesecond tunnel 140 as the indoor air return 142. Accordingly, when thefirst and the second dampers 116 and 120 are both in their closedpositions, vented indoor air entered into the first tunnel 130 isprimarily exhausted after exchanging heat in the core 225.

In the recirculation mode, the first damper 116 is in an open position.A first portion of the vented indoor air from the indoor air intake 132can flow through the first damper 116 into the first recirculation path210A. The first portion of the vented indoor air in the firstrecirculation path 210A can further enter into the second tunnel 140through the second opening 122 as a portion of the indoor air return142. Accordingly, when the first damper 116 is in the open position, thefirst portion of the vented indoor air from the indoor air intake 132 isrecirculated through the first recirculation path 210A into the secondtunnel 140 as a portion of the indoor air return 142. The vented indoorair from the indoor air intake 132 is recirculated back to thecontrolled space.

In the recirculation mode, the second damper 120 is in an open position.A second portion of the vented indoor air from the indoor air intake 132can flow through the first opening 118 into the second recirculationpath 210B. The second portion of the vented indoor air in the secondrecirculation path 210B can further flow through the opened seconddamper 120 into the second tunnel 140 as another portion of the indoorair return 142. Accordingly, when the second damper 120 is in the openposition, the second portion of the vented indoor air from the indoorair intake 132 is recirculated through the second recirculation path210B into the second tunnel 140 as another portion of the indoor airreturn 142. The indoor air from the indoor air intake 132 isrecirculated back to the controlled space. Accordingly, when the firstdamper 116 and the second damper 120 are both in their open positions,at least a portion of the indoor air from the first tunnel 130 isrecirculated through the second tunnel 140 and back into the controlledspace.

It is appreciated that, although the first damper 116 and the seconddamper 120 are depicted to have horizontal blades with linkages operatedwith rotary actuators, the dampers 116 and 120 are not limited thisconfiguration. According to an embodiment, the dampers 116 and 120 canbe vertical blade type dampers. The blades on each of the dampers can bea parallel blade configuration or an opposed blade configuration, or acombination of both. According to another embodiment, the dampers 116and 120 can be any type of damper that obstruct airflow.

In the ventilation mode, energy is recovered in the core 225. The firstdamper 116 is in the closed position and obstructs the vented indoor airin the first tunnel 130 from entering into the first recirculation path210A. The vented indoor air flows into the second recirculation path210B through the first opening 118. The second damper 118 is in theclosed position and obstructs the vented indoor in the secondrecirculation oath 210B from entering the second tunnel 140.Accordingly, the vented indoor air enters into the core 225. Fresh airfrom the environment enters the core 225 through the rear faceplate 114Aand exchanges energy with the vented indoor air in the core 225. Afterpassing the core 225, the fresh air enters into the first recirculationpath 210A. The fresh air is obstructed by the first damper 116 andchanneled into the second tunnel 140 through the second opening 122. Thefresh air in the second tunnel 140 becomes the indoor air return 142 andis further channeled into the controlled space. The vented indoor air isexhausted into the environment after passing the core 225.

According to another embodiment, the core 125 or 225 further includes atleast one of a defrost damper or a bypass damper (not shown). Thedefrost damper, when opened, introduces heated air or indoor air to theheat exchanger in the core 125 or 225, and removes frost on the heatexchanger by warming the heat exchanger with the heated air. The bypassdamper, when opened, conducts vented indoor air to the exhaust withoutpassing through the core 125 or 225.

FIG. 3A is a side view of the air handler to illustrate space savings.As shown in FIG. 3A, the air handler 100 includes the core 125, thefirst recirculation path 110A, and the second recirculation path 110B.The first tunnel 130 connects to the air handler 100 at the first areaof the faceplate 114. A septum 170 connects the core 125 to thefaceplate 114. The second tunnel 140 connects to the air handler 100 atthe second area of the faceplate 114. The first tunnel 130 and thesecond tunnel 140 are separated by the middle of unit wall 150. Duringthe recirculating mode of the air handler 100, vented indoor airrecirculates through the first tunnel 130, the first damper 116, thefirst opening 118, the first and second recirculation paths 110A and110B, the second damper 120, and the second opening 122, and into thesecond tunnel 140. Accordingly, the recirculation function of the airhandler 100 can be accomplished by a distance of L1. The spacerepresented by L1 includes the space for the core 125.

FIG. 3B is a side view of a known air handler to illustrate spacesavings of the air handler 100 of FIG. 3A in comparison to said knownair handler. As shown in FIG. 3B, an air handler 10 includes a core 25.The size or capacity of the core 25 is comparable to the size orcapacity of the core 125 (shown in FIG. 3A). The first tunnel 30connects to the air handler 10 at a first area of a faceplate 14. Thesecond tunnel 40 connects to the air handler 10 at a second area of thefaceplate 14. The first tunnel 30 and the second tunnel 40 are separatedby a middle of unit wall 50. A recirculation damper 52 is includedadjacent to the faceplate 14 on the middle of unit wall 50. During therecirculating mode of the air handler 10, vented indoor air enters thefirst tunnel 30 and is blocked by a first damper and a first block offplate on the first area of the faceplate 14 where the first tunnel 30connects to the faceplate 14. Accordingly, the vented indoor air isforced through the opened recirculation damper 52 into the second tunnel40. The vented indoor air is further blocked by a second damper and asecond block off plate on the second are of the faceplate 14 where thesecond tunnel 40 connects to the faceplate 14. Accordingly, the ventedindoor air flows through the second tunnel 40 back to the controlledspace. The recirculation function of the air handler 10 is accomplishedin a distance of L′ with the core 25 having a similar size and capacityof the core 125 (as shown in FIG. 4A).

As shown by comparing FIGS. 3A and 3B, the damper configurationsaccording to the air handler 100 save a distance of a difference betweenL1 and L1′, for example. This difference is similar to the width of therecirculation damper 52, as shown in FIG. 3B. According to oneembodiment, the recirculation damper 52 can be 24 to 48 inches wide.Accordingly, the space savings of the air handler 100 can be 24 to 48inches.

FIG. 4A is a side view of the air handler 200 to illustrate spacesavings. As shown in FIG. 4A, the air handler 200 includes the core 225,the first recirculation path 210A, and the second recirculation path210B. The first tunnel 130 connects to the air handler 200 at the firstarea of the faceplate 114. A septum 270 connects the core 225 to thefaceplate 114. The second tunnel 140 connects to the air handler 200 atthe second area of the faceplate 114. The first tunnel 130 and thesecond tunnel 140 are separated by the middle of unit wall 150. Duringthe recirculating mode of the air handler 200, vented indoor airrecirculates through the first tunnel 130, the first damper 116, thefirst opening 118, the first and second recirculation paths 210A and210B, the second damper 120, and the second opening 122, and into thesecond tunnel 140. Accordingly, the recirculation function of the airhandler 200 can be accomplished by a distance of L2. The spacerepresented by L2 includes the space for the core 225.

FIG. 4B is a side view of a known air handler 20 to illustrate spacesavings of the air handler 200 of FIG. 4A. As shown in FIG. 4B, an airhandler 20 includes a core 25A. The size or capacity of the core 25A iscomparable to the size or capacity of the core 225 (shown in FIG. 4A).The first tunnel 30 connects to the air handler 10 at a first area of afaceplate 14. The second tunnel 40 connects to the air handler 10 at asecond area of the faceplate 14. The first tunnel 30 and the secondtunnel 40 are separated by a middle of unit wall 50. A recirculationdamper 52 is included adjacent to the faceplate 14 on the middle of unitwall 50. During the recirculating mode of the air handler 10, ventedindoor air enters the first tunnel 30 and is forced through the openedrecirculation damper 52 into the second tunnel 40. Accordingly, thevented indoor air flows through the second tunnel 40 back to thecontrolled space. The recirculation function of the air handler 20 isaccomplished in a distance of L2′ with the core 25A having a similarsize and capacity of the core 225 (as shown in FIG. 4A).

As shown by comparing FIG. 4A and FIG. 4B, the damper configurationsaccording to the air handler 200 save a distance of a difference betweenL2 and L2′. This difference is similar to the width of the recirculationdamper 52, as shown in FIG. 4B. According to one embodiment, therecirculation damper 52 can be 24 to 48 inches wide. Accordingly, thespace savings of the air handler 100 can be 24 to 48 inches.

It is appreciated that pressure drop is inversely proportional to thecross-sectional area of the flow path. Accordingly, when the two airhandlers occupying the same amount of space, the air handler with damperconfiguration according to this disclosure will experience a smallerpressure drop. Additionally, a smaller pressure drop generallycorrelates to more uniformed downstream airflow. Accordingly, when thetwo air handlers occupying the same amount of space, the air handlerwith damper configuration according to this disclosure will have a moreuniformed airflow downstream of air handler.

Aspects. It is noted that any of aspects 1-12 can be combined with anyone of aspects 13-20.

Aspect 1. An air handler for an HVACR system, comprising:

a housing having a faceplate, a roof panel, a base panel, a first sidepanel, and a second side panel;

a septum protruding into the housing from a first side of the faceplate;

a core disposed within the housing and having a front edge connected toan edge of the septum, a top edge connected to the roof panel, a bottomedge connected to the base panel, a first side plate connected to thefirst side panel, and a second side plate connected to the second sidepanel;

a first tunnel connected to a first area on the faceplate from a secondside of the faceplate, wherein the second side is opposite to the firstside of the faceplate;

a second tunnel connected to a second area of the faceplate from thesecond side, wherein the second area is disjointed from the first area;

a first recirculation path defined by the faceplate, the roof panel, theseptum, the first side panel, the second side panel, and the core andconfigured to channel a first portion of airflow from the first tunnelto the second tunnel;

a second recirculation path defined by the faceplate, the septum, thebase panel, the first side panel, the second side panel, and the coreand configured to channel a second portion of the airflow from the firsttunnel to the second tunnel;

a first damper disposed in the first area of the faceplate andconfigured to obstruct the first recirculation path;

a second damper disposed in the second area of the faceplate andconfigured to obstruct the second recirculation path;

a first opening disposed in the first area of the faceplate andconnecting the first tunnel to the second recirculation path; and

a second opening disposed in the second area of the faceplate andconnecting the second tunnel to the first recirculation path.

Aspect 2. The air handler of aspect 1, wherein

the second damper is disposed adjacent to the first side panel and theroof panel, and

the first damper is disposed adjacent to the second side panel and thebase panel.

Aspect 3. The air handler of any one of aspects 1-2, wherein

the second opening is adjacent to the first side panel and the basepanel, and

the first opening is adjacent to the second side panel and the roofpanel.

Aspect 4. The air handler of any one of aspects 1-3, wherein

the first tunnel is an indoor air inlet from a controlled space, and

the second tunnel is an indoor air return to the controlled space.

Aspect 5. The air handler of any one of aspects 1-4, wherein

the core includes a fixed plate heat exchanger or a rotary type wheelheat exchanger.

Aspect 6. The air handler of any one of aspects 1-5, wherein

the core is in a horizontal configuration substantially parallel to theseptum, and

when the core includes a fixed plate heat exchanger, the fixed plateheat exchanger includes heat transfer plates that are in a verticalconfiguration, and.

when the core includes a rotary type wheel heat exchanger the rotarytype wheel heat exchanger includes at least two side-by-side wheels.

Aspect 7. The air handler of any one of aspects 1-6, wherein

the first tunnel and the second tunnel are separated by a middle of unitwall that is substantially perpendicular to the faceplate on a firstplane and substantially perpendicular to the septum on a second plane,wherein the second plane is substantially perpendicular to the firstplane.

Aspect 8. The air handler of any one of aspects 1-7, wherein

the first damper includes a plurality of sections that are configured toopen or close independently among one another or in unison, and

the second damper includes a plurality of sections that are configuredto open or close independently among one another or in unison.

Aspect 9. The air handler of any one of aspects 1-8, wherein

the first damper obstructs the first portion of the airflow fromentering the first recirculation path when the first damper is in aclosed position.

Aspect 10. The air handler of any one of aspects 1-9, wherein

the second damper obstructs the second portion of the airflow fromentering the second tunnel when the second damper is in a closedposition.

Aspect 11. The air handler of any one of aspects 1-10, wherein

the first portion of the airflow is recirculated to the second tunnelthrough the second opening when the first damper is in an open position,and

the second portion of the airflow is recirculated to the second tunnelthrough the first opening and the second recirculation path when thesecond damper is in an open position.

Aspect 12. The air handler of any one of aspects 1-11, wherein

the airflow enters the first tunnel from a controlled space isrecirculated into the controlled space when the first and the seconddampers are in their open positions.

Aspect 13. The air handler of any one of aspect 1-12, wherein

the core further includes at least one of a bypass damper or a defrostdamper.

Aspect 14. A method of providing recirculation capabilities using an airhandler with a core, comprising:

opening a first damper and a second damper;

receiving vented indoor air from a controlled space through a firsttunnel;

channeling a first portion of the vented indoor air from the firsttunnel to a second tunnel through the first damper, a firstrecirculation path, and a second opening;

channeling a second portion of the vented indoor air from the firsttunnel to the second tunnel through a first opening, a secondrecirculation path, and the second damper; and

returning the first portion of the vented indoor air and the secondportion of the vented indoor air from the second tunnel into thecontrolled space, wherein

the air handler has a housing that includes a faceplate, a roof panel, abase panel, a first side panel, and a second side panel,

the first recirculation path and the second recirculation path areseparated by a septum protruding into the housing from a first side ofthe faceplate,

the housing contains the core having a top edge connected to the roofpanel, a bottom edge connected to the base panel, a front edge connectedto the septum, a first side plate connected to the first side panel, anda second side plate connected to the second side panel,

the first tunnel connects to the faceplate at a first area of a secondside of the faceplate, wherein the second side is opposite to the firstside of the faceplate,

the second tunnel connects to the faceplate at a second area of thefirst side of the faceplate, wherein the second area is disjointed fromthe first area,

the first damper and the first opening are disposed in the first area onthe faceplate,

the second damper and the second opening are disposed in the second areaon the faceplate,

the first recirculation path is defined by the roof panel, thefaceplate, the first side panel, the second side panel, the septum, andthe core, and

the second recirculation path is defined by the base panel, thefaceplate, the first side panel, the second side panel, the septum, andthe core.

Aspect 15. The method of aspect 14 further comprising:

closing the first damper and the second damper;

obstructing the vented indoor air in the first tunnel from entering intothe first recirculation path;

channeling the vented indoor air in the first tunnel into the secondrecirculation path through the first opening;

channeling the vented indoor air in the second recirculation path intothe core;

channeling fresh air into the core;

exchanging energy in the core between the vented indoor and the freshair;

channeling the fresh air in the core into the first recirculation path;

obstructing the fresh air in the first recirculation path from enteringinto the first tunnel;

channeling the fresh air in the first recirculation path into the secondtunnel through the second opening;

exhausting the vented indoor air from the core after exchanging energy;and

channeling the fresh air from the second tunnel to the controlled space.

Aspect 16. The method of any one of aspects 14-15, wherein

the second damper is disposed adjacent to the first side panel and theroof panel, and the first damper is disposed adjacent to the second sidepanel and the base panel, and

the first opening is adjacent to the second side panel and the roofpanel, and the second opening is adjacent to the first side panel andthe base panel.

Aspect 17. The method of any one of aspects 14-16, wherein

the first tunnel is an indoor air inlet from the controlled space, and

the second tunnel is an indoor air return to the controlled space.

Aspect 18. The method of any one of aspects 14-17, wherein

the core includes a fixed plate heat exchanger or a rotary type wheelheat exchanger.

Aspect 19. The method of any one of aspects 14-18, wherein

the core is in a horizontal configuration substantially parallel to theseptum, and

when the core includes a fixed plate heat exchanger, the fixed plateheat exchanger includes heat transfer plates of the core are in avertical configuration, and

when the core includes a rotary type wheel heat exchanger the rotarytype wheel heat exchanger includes at least two side-by-side wheels.

Aspect 20. The method of any one of aspects 14-19, wherein

the first tunnel and the second tunnel are separated by a middle of unitwall that is substantially perpendicular to the faceplate on a firstplane and substantially perpendicular to the septum on a second plane,wherein the second plane is substantially perpendicular to the firstplane.

Aspect 21. The method of any one of aspects 14-20, wherein

the first damper includes a plurality of sections that are configured toopen or close independently among one another or in unison, and

the second damper includes a plurality of sections that are configuredto open or close independently among one another or in unison.

The terminology used in this Specification is intended to describeparticular embodiments and is not intended to be limiting. The terms“a,” “an,” and “the” include the plural forms as well, unless clearlyindicated otherwise. The terms “comprises” and/or “comprising,” whenused in this Specification, specify the presence of the stated features,integers, steps, operations, elements, and/or components, but do notpreclude the presence or addition of one or more other features,integers, steps, operations, elements, and/or components.

With regard to the preceding description, it is to be understood thatchanges may be made in detail, especially in matters of the constructionmaterials employed and the shape, size, and arrangement of parts withoutdeparting from the scope of the present disclosure. This Specificationand the embodiments described are exemplary only, with the true scopeand spirit of the disclosure being indicated by the claims that follow.

What is claimed is:
 1. An air handler for an HVACR system, comprising: ahousing having a faceplate, a roof panel, a base panel, a first sidepanel, and a second side panel; a septum protruding into the housingfrom a first side of the faceplate; a core disposed within the housingand having a front edge connected to an edge of the septum, a top edgeconnected to the roof panel, a bottom edge connected to the base panel,a first side plate connected to the first side panel, and a second sideplate connected to the second side panel; a first tunnel connected to afirst area on the faceplate from a second side of the faceplate, whereinthe second side is opposite to the first side of the faceplate; a secondtunnel connected to a second area of the faceplate from the second side,wherein the second area is disjointed from the first area; a firstrecirculation path defined by the faceplate, the roof panel, the septum,the first side panel, the second side panel, and the core and configuredto channel a first portion of airflow from the first tunnel to thesecond tunnel; a second recirculation path defined by the faceplate, theseptum, the base panel, the first side panel, the second side panel, andthe core and configured to channel a second portion of the airflow fromthe first tunnel to the second tunnel; a first damper disposed in thefirst area of the faceplate and configured to obstruct the firstrecirculation path; a second damper disposed in the second area of thefaceplate and configured to obstruct the second recirculation path; afirst opening disposed in the first area of the faceplate and connectingthe first tunnel to the second recirculation path; and a second openingdisposed in the second area of the faceplate and connecting the secondtunnel to the first recirculation path.
 2. The air handler of claim 1,wherein the second damper is disposed adjacent to the first side paneland the roof panel, and the first damper is disposed adjacent to thesecond side panel and the base panel.
 3. The air handler of claim 2,wherein the second opening is adjacent to the first side panel and thebase panel, and the first opening is adjacent to the second side paneland the roof panel.
 4. The air handler of claim 1, wherein the firsttunnel is an indoor air inlet from a controlled space, and the secondtunnel is an indoor air return to the controlled space.
 5. The airhandler of claim 1, wherein the core includes a fixed plate heatexchanger or a rotary type wheel heat exchanger.
 6. The air handler ofclaim 5, wherein the core is in a horizontal configuration substantiallyparallel to the septum, and when the core includes the fixed plate heatexchanger, the fixed plate heat exchanger includes heat transfer platesthat are in a vertical configuration, and when the core includes therotary type wheel heat exchanger, the rotary type wheel heat exchangerincludes at least two side-by-side wheels.
 7. The air handler of claim1, wherein the first tunnel and the second tunnel are separated by amiddle of unit wall that is substantially perpendicular to the faceplateon a first plane and substantially perpendicular to the septum on asecond plane, wherein the second plane is substantially perpendicular tothe first plane.
 8. The air handler of claim 1, wherein the first damperincludes a plurality of sections that are configured to open or closeindependently among one another or in unison, and the second damperincludes a plurality of sections that are configured to open or closeindependently among one another or in unison.
 9. The air handler ofclaim 1, wherein the first damper obstructs the first portion of theairflow from entering the first recirculation path when the first damperis in a closed position.
 10. The air handler of claim 1, wherein thesecond damper obstructs the second portion of the airflow from enteringthe second tunnel when the second damper is in a closed position. 11.The air handler of claim 1, wherein the first portion of the airflow isrecirculated to the second tunnel through the second opening when thefirst damper is in an open position, and the second portion of theairflow is recirculated to the second tunnel through the first openingand the second recirculation path when the second damper is in an openposition.
 12. The air handler of claim 1, wherein the airflow enteredthe first tunnel from a controlled space is recirculated into thecontrolled space when the first and the second dampers are in their openpositions.
 13. The air handler of claim 1, wherein the core furtherincludes at least one of a bypass damper, or a defrost damper.
 14. Amethod of providing recirculation capabilities using an air handler witha core, comprising: opening a first damper and a second damper;receiving vented indoor air from a controlled space through a firsttunnel; channeling a first portion of the vented indoor air from thefirst tunnel to a second tunnel through the first damper, a firstrecirculation path, and a second opening; channeling a second portion ofthe vented indoor air from the first tunnel to the second tunnel througha first opening, a second recirculation path, and the second damper; andreturning the first portion of the vented indoor air and the secondportion of the vented indoor air from the second tunnel into thecontrolled space, wherein the air handler has a housing that includes afaceplate, a roof panel, a base panel, a first side panel, and a secondside panel, the first recirculation path and the second recirculationpath are separated by a septum protruding into the housing from a firstside of the faceplate, the housing contains the core having a top edgeconnected to the roof panel, a bottom edge connected to the base panel,a front edge connected to the septum, a first side plate connected tothe first side panel, and a second side plate connected to the secondside panel, the first tunnel connects to the faceplate at a first areaof a second side of the faceplate, wherein the second side is oppositeto the first side of the faceplate, the second tunnel connects to thefaceplate at a second area of the first side of the faceplate, whereinthe second area is disjointed from the first area, the first damper andthe first opening are disposed in the first area on the faceplate, thesecond damper and the second opening are disposed in the second area onthe faceplate, the first recirculation path is defined by the basepanel, the faceplate, the first side panel, the second side panel, theseptum, and the core, and the second recirculation path is defined bythe roof panel, the faceplate, the first side panel, the second sidepanel, the septum, and the core.
 15. The method of claim 14 furthercomprising: closing the first damper and the second damper; obstructingthe vented indoor air in the first tunnel from entering into the firstrecirculation path; channeling the vented indoor air in the first tunnelinto the second recirculation path through the first opening; channelingthe vented indoor air in the second recirculation path into the core;channeling fresh air into the core; exchanging energy in the corebetween the vented indoor and the fresh air; channeling the fresh air inthe core into the first recirculation path; obstructing the fresh air inthe first recirculation path from entering into the first tunnel;channeling the fresh air in the first recirculation path into the secondtunnel through the second opening; exhausting the vented indoor air fromthe core after exchanging energy; and channeling the fresh air from thesecond tunnel to the controlled space.
 16. The method of claim 14,wherein the second damper is disposed adjacent to the first side paneland the roof panel, and the first damper is disposed adjacent to thesecond side panel and the base panel, and the first opening is adjacentto the second side panel and the roof panel, and the second opening isadjacent to the first side panel and the base panel.
 17. The method ofclaim 14, wherein the first tunnel is an indoor air inlet from thecontrolled space, and the second tunnel is an indoor air return to thecontrolled space.
 18. The method of claim 14, wherein the core includesa fixed plate heat exchanger or a rotary type wheel heat exchanger. 19.The method of claim 14, wherein the core is in a horizontalconfiguration substantially parallel to the septum, and when the coreincludes the fixed plate heat exchanger, the fixed plate heat exchangerincludes heat transfer plates that are in a vertical configuration, andwhen the core includes the rotary type wheel heat exchanger, the rotarytype wheel heat exchanger includes at least two side-by-side wheels. 20.The method of claim 14, wherein the first tunnel and the second tunnelare separated by a middle of unit wall that is substantiallyperpendicular to the faceplate on a first plane and substantiallyperpendicular to the septum on a second plane, wherein the second planeis substantially perpendicular to the first plane.